This invention relates to lipid-containing foodstuffs and feed supplements. One aspect of this invention relates to a process for making processed meat products such as sausage and bologna that contain microencapsulated fat. Another aspect of the invention relates to a process for microencapsulating lipids in either animal or vegetable protein. A further aspect of the invention relates to animal foodstuffs produced by treating animal processing wastes from meat packing plants. In still another aspect, this invention relates to ruminant feed supplements characterized by their high lipid content and their ability to pass through the rumen substantially unchanged for subsequent digestion in the abomasum and lower gut of the ruminant animal.
Many processes for treating proteinaceous materials are disclosed by earlier references such as U.S. Pat. Nos. 3,137,631; 3,821,453 and 3,925,560. While these earlier teachings disclose processes for denaturing proteins by treating them with acid, alkali and aldehydes, or by subjecting them to high temperatures and pressures, a need still exists for an effective process to microencapsulate lipids within dietary proteins in the production of foodstuffs for humans and other animals.
The meat processing industry has long sought methods for incorporating fat and water within meat products such as sausage and bologna. Two problems are commonly associated with the manufacture of such products. One problem relates to frictional heating that occurs during mixing of emulsion type processed meat. Unless ice is added during emulsification, the fat dispersed throughout the meat will melt and separate therefrom. The other problems relates to the separation of fat and water from such products during cooking. This separation not only results in product shrinkage, but also reduces the desirable juiciness that is ordinarily attributable to higher fat and moisture content within the cooked product.
Other problems faced by the meat processing industry relate to the production of canned meats intended for consumption by either humans or domestic pets. The high energy value associated with fats makes their incorporation in such canned meat products highly desirable. However, when processed according to methods previously known, fats have demonstrated a tendency to migrate out of the product and collect at the container wall or float to the top of the can, spoiling the comestic appearance of the product.
Another problem relates to the manufacture of canned soups. Fat contained in soups manufactured according to presently known processes tends to separate and float on the surface during cooking.
Because of the increasing concern about heart disease associated with high saturated fat diets, there is also a need for food products having a low saturated fat content. A problem has previously existed in producing such products in a form that is palatable, yet adequate for the dietary needs of people concerned about heart disease. This invention will permit the inclusion of polyunsaturated vegetable oils into meat protein in a stable form that will not separate out during cooking. This process will greatly enhance the flavor and palatability of such dietary products.
Additionally, the meat processing industry has long sought better methods of utilizing animal bones and other nutritive waste materials. The present invention provides an efficient way of utilizing such materials to form nutritious animal feed supplements without the disadvantages associated with heat rendering and extraction processes formerly used.
Because meat, meat by-products and milk all contain large amounts of fat, an aim of modern livestock feeding techniques is to increase the amount of lipids ingested by the animals. Currently, most of the lipid materials used to supplement stock feeds are incorporated in a liquid form. Hot liquid lipids are sprayed onto the other nutritional ingredients and allowed to coalesce before feeding. One disadvantage of this method is that such feeds cannot be stored for any appreciable amount of time because of their tendency to turn rancid, to become contaminated, and to attract insects. Furthermore, ruminant animals present a special problem with regard to lipid supplemented feeds. High fat diets fed to ruminants in a free fat form have been found to cause severe gastric upset, resulting in loss of appetite and decreased weight gain. The protein-encapsulated lipids of the present invention will effectively resist diegestion in the rumen, and thereby avoid associated gastric upset.